Device and method for eliminating trimmings from series of products, such as rolls or the like

ABSTRACT

The device comprises at least a continuous movable flexible member ( 23 ) carrying a series of contact members ( 29, 29 A,  29 B) for the products (R; R 1 ; RN) aligned with one another. A section of the movable flexible member is devoid of said contact members to allow the trimmings (Rc, Rt) to fall. At least a longitudinal supporting element (21) of the products (R; R 1 , RN), is also provided, parallel to the movable flexible member, the reciprocal position of said flexible member and of said longitudinal element being such that the products advance in contact with the contact members (29, 29A, 29B) of the flexible member and with the longitudinal element. A pusher ( 11 ) inserts the series of products with the respective trimmings between the flexible member and the longitudinal supporting member. The flexible member ( 23 ) is controlled with a variable speed to carry the section thereof devoid of contact members time by time to the level of the head and tail trimmings (Rc, Rt) of two consecutive series of products.

TECHNICAL FIELD

The invention relates to a device to remove scraps or end trimmings inthe production of rolls of wound web material, such as paper or thelike, for example to produce rolls of toilet tissue, kitchen towels orthe like, produced by cutting longer rolls, or “logs”, into severalparts.

More generally, the present invention relates to a device to eliminatetrimmings or scraps from series or rows of products.

STATE OF THE ART

The production of rolls of wound web material, such as toilet tissue,kitchen towels and the like, is performed by cutting a log, that is, anoriginal roll with a diameter the same as the final rolls but of a muchgreater length than rolls destined for use, into several parts. The logis then cut into several parts by cutting machines, in order to obtainrolls of the desired length. During this operation head and tailtrimmings or scraps are produced at both ends of the log, to discard theportion of edge material which is often damaged and in any case woundirregularly. By cutting the trimmings, rolls of the desired axial lengthare also obtained, even when the width of the initial web material isnot an exact multiple of the height of the rolls.

These scraps or trimmings must be eliminated from the production lineprior to packaging or wrapping, to be recovered by recycling thematerial if necessary, preventing clogging of wrapping machines.

Various machines have been developed to eliminate these scraps. Somemachines use a procedure which makes use of pneumatic suction devices tohold the rolls while the trimmings are made to fall. Systems of thistype are described in EP-A-607761 and in U.S. Pat. No. 5,458,033. Inthese known devices a conveyor with suction belt engages the rolls fromabove while the trimmings are not held by the belt conveyor and fall asa result of gravity to an area between a feed conveyor and a deliveryconveyor of the rolls.

WO-A-0162635 describes a further device to eliminate trimmings based onthe use of a flexible suction member which holds the rolls from aboveand makes them advance through the device, while areas devoid of suctionof the flexible member are positioned at the level of the head and tailtrimmings of each series of rolls.

GB-A-2137918 describes a device to eliminate trimmings from series ofrolls obtained by cutting a log, comprising a continuous movableflexible member with a series of contact members for the productsaligned with one another. A section of said movable flexible member isdevoid of contact members to allow the trimmings to fall. This flexiblemember extends parallel to a smooth belt, movable at the same speed asthe advance speed of the flexible member. This belt constitutes alongitudinal supporting element for the products. The products travel incontact with the contact members of the flexible member and with thesmooth belt. The rolls and the trimmings are pushed along the pathdefined by the flexible member with the contact members and by thesmooth belt by means of a series of pushers integral with a chain orbelt conveyor disposed upstream of the device to eliminate trimmings.The trimmings are eliminated thanks to the fact that in the area inwhich the continuous flexible member is devoid of contact or supportingmembers, the trimmings have no support and fall as a result of gravity.The flexible member provided with contact members to support the rollsand to make the trimmings fall, must extend for a length equal to thelength of the logs increased by the distance between consecutive logs.The device is therefore extremely bulky and cannot be adapted forproducts with different lengths.

This device is particularly efficient but not easily adaptable to thedifferent dimensions of the rolls and of the logs to be handled.

Another system to eliminate trimmings is described in U.S. Pat. No.4,265,361, in which all rolls of a size sufficiently small to escapefrom a series of engaging members positioned at a congruous distance areallowed to fall from the line.

WO-A-9732804 describes a system to eliminate head and tail scraps ortrimmings based essentially on the roll conveying line being formed ofthree different sections. The first section is characterized by thepresence of a pusher which pushes the rolls fed from the cutting machinealong a guide or channel. The second section is characterized by thesimultaneous presence of two motorized conveyor belts disposed under thepath of the rolls. These provide support and transport for the rolls.The pusher is also present in this second section, and although it doesnot transport the rolls, which are transported by the two belts, ittravels along part of this second section before being drawn back by thechain with which it is integral. The two belts of the second section ofthe path of the rolls are of different lengths and a bar forming a fixedsupport is positioned adjacent to the shorter belt. The bar is at agreater height than the two belts, one of which extends parallel to thebar. The trimmings are discarded in this third section.

IT-B-01292359 describes a system to eliminate head and tail trimmingsfrom rows of cut rolls, which is based on the difference between theaxial dimension of a roll destined for packaging and the axial dimensionof a trimming. The rolls and trimmings are disposed on a conveyor lineconstituted by two parallel belt means, positioned at adjustabledistances from each other, advancing in the same direction and at thesame speed. The reciprocal distance of the two belt means is equivalentto the axial dimension of the rolls and therefore is greater than theaxial dimension of the trimmings.

The trimmings are therefore eliminated owing to the fact that thereduced axial dimensions of the trimmings prevent simultaneous contactwith both belts, so that the lack of support consequently causes thetrimmings to fall from the lower belt. In order to operate, the devicerequires both the rolls and the trimmings to be fed into the pathdefined by the two overlapping belts, to be overturned and hence to lieon one of their flat faces. The device cannot function if the rolls andtrimmings (or at least the latter) are fed in the position in which theyare delivered from the cutting machine, that is, with their axisparallel to the feed path and hence parallel to the two belts.Therefore, upstream the device requires a system to overturn the rollsand trimmings, or at least the trimmings.

Similar problems may occur in other situations in which it is necessaryto eliminate trimmings or scraps from series or rows of productsobtained from cutting a semi-finished product of larger dimensions, oreven simply from series of articles or manufactured products advancingalong a processing line.

OBJECTS AND SUMMARY OF THE INVENTION

The object of the present invention is to provide a device to removescraps or head and tail trimmings in series of aligned rolls, which issimple and reliable also at high operating speeds, with limiteddimensions and which can also be easily adapted for different diametersand axial dimensions of cut rolls and for series containing a variablenumber of rolls.

More generally, the object of the present invention is to provide adevice to eliminate scraps or trimmings from rows or series of articlesor products advancing along a processing line, such as in particular(although not exclusively) series of rolls obtained by cutting logs.

According to a different aspect, the object of the invention is to offeran effective and reliable method to eliminate head and tail trimmingsfrom series of products, in particular series of rolls obtained bycutting logs crosswise.

The device according to the invention comprises a conveyor or flexiblemember provided with contact or supporting elements or members, whichsupport the products, and a longitudinal supporting element, extendingparallel to a branch of the flexible member, wherein characteristicallythe flexible member is controlled at a variable speed and thelongitudinal supporting element is preferably fixed.

With this configuration, contrary to the arrangement in, for example,GB-A-2137918, the device can easily be adapted to series of products ofvariable lengths and to products of variable dimensions without the needto adjust the mechanical configuration of the members thereof and hencewithout adaptations. In fact, as shall be apparent from the descriptionof an example of embodiment, only the advance speed of the flexiblemember requires to be adjusted. The flexible member with controllablespeed can be phased suitably to carry the section devoid of contactmembers to the level of the position of the head and tail trimmings ofconsecutive series of products. When the length of the series ofproducts changes, and/or the distance between one series and the nextchanges, by setting a cyclic variation of the advance speed of theflexible member the area thereof devoid of contact members for theproducts to be handled can be phased in relation to the position of thehead and tail trimmings of each series. In general, the flexible membercan also be much shorter in length than the series of products (forexample series of rolls cut from a log), with an advantage in terms ofoverall dimensions of the device, as well as advantages of greaterflexibility and easy adaptability to the various product dimensions.

According to a possible configuration, forming an object of theinvention, the device can be of the type comprising: at least acontinuous movable flexible member carrying a series of contact membersfor the products aligned with one another, a section of said movableflexible member being devoid of said contact members to allow trimmingsto fall; at least a longitudinal element to support the products,parallel to said movable flexible member, the reciprocal position ofsaid flexible member and of said longitudinal element being such thatthe products advance in contact with the contact members of the flexiblemember and with the longitudinal element; at least a pusher to insertthe series of products with respective trimmings between said flexiblemember and said longitudinal supporting element. Characteristically, theflexible member is controlled with a variable speed to carry the sectionthereof devoid of contact members time by time to the level of the tailand head trimmings of two consecutive series of products. The supportingelement is preferably fixed and the products run thereon. Thissimplifies the structure and increases the reliability of the device.

In an advantageous embodiment, the continuous flexible member has atleast a first contact member designed to grasp at least the last productof each series and make it advance. Preferably, it is also provided withat least a second contact member designed to grasp at least the firstproduct of each series and make it advance. The intermediate contactmembers, not specifically designed to grasp the end products of eachseries, are advantageously and preferably produced with a productcontact having a low friction coefficient, to allow said products toslide with respect to said supporting members.

The flexible member can advantageously be controlled at a variable speedto accelerate at least the last product of each series with respect tothe pusher therebehind. Moreover, according to an improved embodiment ofthe invention, the flexible member can be controlled at a variable speedto accelerate and, if necessary, subsequently decelerate at least thefirst product of each series with respect to the subsequent product.

To produce a compact device, the flexible member can be controlled toadvance at a lower speed or to stop during an interval of time betweenarrival of the first product and arrival of the last product of eachseries, the products being pushed by the pusher and sliding along theflexible member resting on the supporting member during said interval oftime.

Advantageously, at least one of said contact members can be operated tohave an grasping action on the products in contact therewith, forexample by being pressed against the product with which it is incontact. For example and in particular, the engaging element providedwith this capacity is the last engaging element disposed along theflexible member, that is, the one which engages the last product of eachseries of products, such as the last roll of a row of rolls obtained bycutting a log, ahead of the tail trimming.

In this way, the last roll can be accelerated in a reliable way todistance it from the tail trimming and also from the pusher which pushesthe row or series of rolls or other products along the device. This onthe one hand guarantees that the tail trimming is devoid of support infront and behind and therefore falls from the longitudinal supportingelement, and on the other distances the rolls from the pusher, which canturn about the return wheel of the chain or belt on which it is mountedto return and engage a subsequent series of products, withoutinterfering with the products of the series already inserted by saidpusher in the device to eliminate trimmings. Preferably, at least two ormore adjacent contact members are equipped to have an grasping action onthe last product or roll of the series. This guarantees a safer hold andtherefore improved control of the movement to accelerate the rolls.

In a preferred embodiment of the invention, the first contact member ormembers of the series of contact members carried by the flexible membercan also be operated to grasp the products using pressure. This or thesefurther contact members are destined to cooperate with the first productof each row or series, that is, with the product directly behind thehead trimming. The grasping action on this roll allows it to beaccelerated and, if necessary, subsequently decelerated, giving a sortof thrust or impact to the head trimming which, devoid of the support ofthe contact members will be overturned and fall, thus being eliminated.

For example, the contact members which can be operated to grasp theproducts can be mounted movable, with respect to the flexible member onwhich they are carried, at least in a direction essentially orthogonalto said flexible member. Or instead, each of these members can have anelement movable with respect thereto. In both cases the contact memberor movable element thereof can be moved to press against the product itmust grasp, moving towards the longitudinal supporting element.

In a particularly advantageous embodiment of the invention, the contactmembers destined to have an grasping action on the rolls can have amovable portion or element, on which a fixed control profile acts, anelastic element being provided to hold said movable portion in contactwith said fixed control profile.

In this way, while the flexible member advances along the controlprofile, the contact members, equipped with the movable portion operatedby the control profile cooperate like a feeler with the control profile,which acts as a cam on the movable portion, pushing it against theproduct to be grasped. The control profile can have a length limited tothe section of path along which it is necessary to grasp the rolls. Thisconfiguration is particularly advantageous, as grasping of rolls by thesupporting members is obtained without the need for actuator elements,but thanks to the simple movement of the flexible member which carriesthe contact members and the fixed shaped profile, which acts as a cam.However, it would also be possible to use different systems, for exampleby providing the various contact members destined to grasp the rollswith specific actuator means, although this results in furthercomplication, also due to the need to supply power to these memberswhile they are moving.

In a particularly advantageous embodiment of the invention, the flexiblemember and the fixed longitudinal element are approximately verticallyoverlapped with each other, with the fixed longitudinal supportingelement under the flexible member.

To allow the pusher to enter the path defined by the flexible member andby the fixed longitudinal supporting element without interfering withthese components, in an advantageous embodiment the pusher has a slotinside which the fixed longitudinal element penetrates when said pusherpushes the products between the fixed longitudinal element and theflexible member. This allows a particularly simple and compact device tobe obtained, without the need to provide further belts or other membersfor roll handling.

The contact members carried by the flexible member can advantageouslyhave a contact surface for the products to be handled having a lowfriction coefficient, to allow sliding of the products grasped by saidcontact members. In this way the products can slide with respect to thecontact members. This condition occurs, for example, when (in order tomaintain phasing of the contact members for the products and of the areaof the flexible member devoid of contact members for the head and tailtrimmings) the flexible member is decelerated and the products advancewith respect thereto under the push of the pusher therebehind.Similarly, the fixed longitudinal element will also have a low frictioncoefficient, at least along the edge in contact with the products to behandled. For example, products such as Teflon® or other similar productscan be used.

According to a different aspect, the invention relates to a method toeliminate head and tail trimmings from series of aligned products,wherein a series of products is pushed by a pusher between alongitudinal supporting element and a continuous movable flexible memberequipped with contact members, the contact members supporting theproducts which advance between the flexible member and the longitudinalsupporting element, the flexible member having a section devoid ofcontact members at the level of the head and tail trimmings of theseries of products to cause said trimmings to fall. Characteristically,the method according to the invention entails: holding the longitudinalsupporting element fixed while making said products slide along saidsupporting element; by means of variation in the speed of the flexiblemember, causing acceleration of at least the last product of each seriesto distance said product from said pusher.

The invention also relates to a method to eliminate head and tailtrimmings from series of aligned products, wherein a series of productsis pushed by a pusher between a longitudinal supporting element and acontinuous movable flexible member equipped with contact members, saidcontact members being in contact with the products advancing betweensaid flexible member and said longitudinal supporting element, saidflexible member having a section devoid of contact members at the levelof the head and tail trimmings of said series of products to cause saidtrimmings to fall. Characteristically, said flexible member iscontrolled at a variable speed to carry the section thereof devoid ofcontact members each time to the level of the head and tail trimmings oftwo consecutive series of products, also with the flexible member havinga length which is less than the length of the series of products.

Further advantageous characteristics and embodiments of the device andof the method according to the invention are indicated in the appendedclaims and shall be described in greater detail hereunder with referenceto an example of embodiment of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention shall now be better understood by following thedescription and accompanying drawing showing a non-limiting practicalembodiment of the invention. More specifically, in the drawing:

FIGS. 1 to 4 show, in schematic side views, the device in four separateoperating phases, FIG. 1A being an enlargement of the detail A in FIG.1;

FIG. 5 shows a section according to V-V in FIG. 1;

FIGS. 6A and 6B schematically show a front view of a contact memberwhich can be operated to grasp the roll, in two different positions;

FIGS. 7A and 7B show the same members in FIGS. 6A and 6B operating withrolls with a larger diameter;

FIG. 8 shows as schematic side view of a different embodiment of theinvention;

FIG. 9 shows a cross section of one of the return wheels around whichthe flexible member is entrained, showing contact members having agripping action;

FIG. 10 shows a side view of one of the contact members having agripping action in isolation;

FIG. 11 shows a cross section similar to FIG. 9, along line XI-XI ofFIG. 8; and

FIG. 12 shows a side view of one of the contact members in isolation.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION

With initial reference specifically to the schematic side views in FIGS.1 to 4 and to the section in FIG. 5, the device, indicated as a wholewith 1, is positioned downstream of a cutting machine 3 represented onlyschematically and comprising an circular knife T or other equivalentcutting member, such as a band saw, to divide logs L of a considerablelength into series of rolls R of a length the same as the length of thefinished product. The cutting machine 3 also produces for each log ahead trimming Rt and a tail trimming Rc, which must be eliminated fromthe device 1, while the rolls R must be transferred to a conveyor 7which then transfers them towards packaging machines of a known type andnot shown. Cutting machines of this type are known and shall not bedescribed herein.

The cutting machine 3 may have one or more channels. The exampleillustrated shows only two adjacent channels (FIG. 5), along which logsand therefore series of rolls in parallel, cut simultaneously by thecutting machine 3, advance. The arrangement of a variable number ofchannels is known to those skilled in the art and does not requireparticular descriptions. Hereunder, reference shall normally be made toone channel, it being understood that each channel has similar membersto eliminate trimmings and to make the logs and cut rolls advance.Especially when a high number of adjacent channels are provided, theposition of the pushers and of the logs along the various channels canbe phased (in a known way) to optimize the position with respect to themovement of the blade T of the cutting machine.

The rolls R produced by cutting each log L by means of the cuttingmachine 3 advance along a guide 9 under the push of a respective pusher11 connected to a chain 13 or other suitable flexible member. Severalpushers are fixed to the chain 13 in suitable positions, according to aknown layout. These are also used to make the logs advance through thecutting machine. The chain 13 is driven about return wheels, one ofwhich can be seen in FIGS. 1 to 4 and indicated with 15. This wheel ismotorized by a motor indicated schematically with 17, interfaced with acontrol unit 19. Both the motor 17 and the control unit 19 are onlyshown in FIG. 1 for clearer and simpler representation.

Disposed between the chain 13 and the delivery conveyor 7 is a fixedlongitudinal supporting element 21, having a laminar configuration,arranged according to a vertical plane. It has a rounded upper edge 21Aalong which the rolls R slide, being made to advance, in the mannerdescribed below, towards the conveyor 7. The element 21 is shaped at theend facing the cutting machine 3 to have a thinner portion 21B, destinedto penetrate a slot or slit 11A produced in the pusher 11, as can beseen in particular in FIG. 5. This allows the pusher 11 to advance alongthe trajectory thereof which turns about the axis of the return wheel15, said axis being positioned under the element 21. The longitudinalsupporting element 21 could also have the shape of a bar, for examplewith a circular section, mounted cantilevered, so that the end thereoffacing the cutting machine 3 can penetrate the slot 11A provided on thepusher 11 and allow the pusher to travel along the trajectory thereof.

Extending above the fixed longitudinal supporting element 21 andessentially aligned vertically therewith, is a flexible member 23, inthe example shown formed of a pair of chains driven about a pair oftoothed return wheels 25, 27. The toothed wheels 27 are motorized by amotor indicated schematically with 28 in FIG. 1, interfaced with thecentral unit 19. The motor 28, just as the motor 17, is anelectronically controlled variable speed motor, for the purposes to beexplained hereunder.

Disposed along a portion of the flexible member 23 are a series ofcontact members 29, adjacent to one another, destined to form a supportfor the rolls R made to advance in the device 1. As can be seen inparticular in FIGS. 5 to 7, all the members, with the exception of thethree initial members 29A and the three final members 29B are composedof simple V-shaped bodies, where the V-shaped surface, indicated with29S is destined to come into contact with the upper surface of the rollsR.

The members 29A and the members 29B, which constitute the end members ofthe series of contact members carried by the flexible member 23, delimita section or portion of the flexible member 23 which is devoid of saidcontact members. This section devoid of contact members 29, 29A, 29B isphased with respect to the position of the pushers and of the head andtail trimmings Rt and Rc, so that the trimmings of each series of rollsare always positioned at the level of the section devoid of contactmembers 29, 29A, 29B.

Each of the end contact members 29A, 29B is equipped with a movableportion or element, constituted by a bracket 31, also V-shaped, made ofor coated with a material with a high friction coefficient, which mayalso be deformable, such as rubber or the like. This bracket is normallyhoused in a groove produced in the surface 29S. Each of said brackets isintegral with a pin 33 projecting from the opposite side of the flexiblemember 23. A helical compression spring 35 is associated with each pin33 to react against a shoulder produced in a through seat formed in themember 29A or 29B and against a boss defined by a head 33T of said pin33. In substance, the helical spring 35 forces the bracket 31 to remainretracted in the seat produced in the V-shaped surface 29S, withoutprojecting therefrom.

Disposed along at least a portion of the lower branch of the flexiblemember 23 is a fixed control profile 37, with respective inclined endportions, forming cam profiles. This control profile acts on the heads33T of the pins 33 when they pass under the profile and produce a thrustthereon which causes the respective brackets 31 to project from theseats thereof for the purposes explained hereunder.

The device described above operates as follows. FIG. 1 shows the instantin which the first roll R1 of the series of rolls pushed by the pusher11 comes into contact with the lower fixed longitudinal supportingelement 21 and with the initial contact members 29A carried by theflexible member 23. As can be observed in detail in FIG. 1A, thesecontact members 29A are made to project downwards by the control profile37. In this way the roll R1 is gripped firmly by the members 29A andmore particularly by the brackets 31 thereof. This allows the flexiblemember 23 to accelerate even suddenly to ensure that the roll R1 isdrawn forward according to the arrow F. In fact, in FIG. 1 the roll R1is shown slightly detached from the subsequent roll, representing thefact that this roll has been accelerated with respect to the speedimparted thereto and to the subsequent rolls R by the pusher 11 andtherefore by the motor 17. In actual fact, acceleration could also bedelayed with respect to the instant represented in FIG. 1, for exampleit could be imparted only after all three contact members 29A havefirmly grasped the roll R1. The rolls upstream of the roll R1 could bedrawn by the contact members 29 or slide with respect thereto, due tothe fact that the surfaces 29S of said members have a low frictioncoefficient. In the example shown it has been hypothesized that theacceleration imparted by the flexible member 23 only accelerates thefirst roll R1 grasped by the contact members 29A.

Acceleration of the first roll R1 of the row or series of rolls pushedby the pusher 11 also causes accelerated advance of the head trimmingRt. This is not in contact with any contact member 29, as it is locatedin the section of flexible member 23 devoid of said members 29.Therefore, as it cannot remain balanced on the upper edge 21A (which isalso rounded) of the thin longitudinal element 21, it falls. Thisproduces efficient and reliable removal of the head trimming Rt. It mustbe noted that elimination is obtained even when the device operates athigh speed. To further increase reliability of the device initialacceleration of the roll R1 can be followed by deceleration thereof, toensure that the support behind of the head trimming Rt is removed. Thesurfaces 29S of the contact members 29 devoid of brackets 31 carried bythe flexible member 23 allow easy relative sliding between thesesurfaces and the rolls R, so that the members 29 can be made to advanceat a different speed (higher or lower) than the speed at which the rollsR advance under the push of the pusher 11.

In practice, the contact members 29 devoid of brackets 31 are disposed,with respect to the rolls R, so that they only graze said rolls, toprovide the rolls with support only. This facilitates advance of therolls R under the push of the pusher without the contact members 29impeding advance thereof even if the members and the rolls havedifferent speeds. This allows the flexible member 23 carrying thecontact members 29 to be decelerated or stopped in a suitable positionduring the passage of a series of rolls, after the head trimming hasbeen discarded.

FIG. 2 shows an instant preceding arrival, under the flexible member 23,of the last roll RN and of the tail trimming. Rc of the series of rollspushed by the pusher 11. In this phase the flexible member 23 canadvance at an essentially lower speed than the speed at which the pusher11 advances. In practice, however, in the layout in FIG. 2, the flexiblemember 23 could also be steady, while the rolls R, pushed by the pusher11, are sliding underneath. The contact members 29 in this phase actonly as a guide to prevent the rolls, which advance to the conveyor 7,from falling. This conveyor can advance, if need be, at speeds higherthan the speed at which the rolls R are fed thereto, to producereciprocal separation between consecutive rolls.

As can be seen in FIG. 2, the last roll RN is delayed with respect tothe position of the last end contact members 29B, so that if the rolls Rand the flexible member 23 were to advance in this phase at the samespeed, only one of the contact members 29B would grasp the roll RN. Inactual fact, as indicated above, the flexible member 23 can betemporarily stopped or made to advance at a lower speed than the speedof the rolls, so that the roll RN recovers space.

An opposite situation can also occur, in which the roll RN is too faradvanced with respect to the position of the end contact members 29B. Ifthis occurs these members 29B must not be allowed to grasp the tailtrimming Rc. For this purpose the speed can once again be regulated, inthis case accelerating the flexible member 23.

FIG. 3 represents the instant in which the last roll RN of the series,that is, the one adjacent to the tail trimming Rc, has been grasped bythe three end contact members 29B. The flexible member 23 has beenaccelerated to the advance speed of the rolls.

To guarantee entirely reliable elimination of the tail trimming Rc, themotor 28 at this point causes temporary acceleration of the flexiblemember 23 to reach a speed higher than the advance speed of the pusher11, so that the rolls R, RN are drawn by the contact members 29B anddistanced from the tail trimming Rc and from the pusher 11. Also in thiscase acceleration is guaranteed (as in the case of acceleration of theroll R1) by the fact that the contact members 29B are equipped withbrackets 31 which, thrust downwards to press against the roll RN throughthe effect of the control profile 37, guarantee grasping of said roll.This makes it possible to maintain control on the roll RN and to impartthe necessary acceleration thereon (and on the rolls downstream thereof)to distance it from the tail trimming Rc and from the pusher 11. As canbe seen in FIG. 4, the tail trimming Rc thereby remains devoid ofsupport and falls to be eliminated. Moreover, the pusher 11 can travelalong the trajectory of rotation thereof about the axis of the wheel 15without impediment and without having to decelerate or stop to distancethe last roll Rn of the series.

The pusher 11 continues to advance along the trajectory defined by thechain 13, driven about the return wheel 15 and continues for a certainsection to advance parallel to the fixed longitudinal supporting element21, the tapered portion 21B of which penetrates the slot 11A.

Extension of the profile 37 for the entire length of the lower branch ofthe flexible member 23 ensures reliable control of the last roll RNwhich is grasped by the brackets 31, to guarantee that all the rolls arepushed onto the conveyor 7.

FIGS. 6A, 6B and 7A, 7B show how the device can be easily used withrolls even with greatly varying diameters. For this purpose, theflexible member 23 and the relative controls can be disposed on a pairof vertically adjustable side elements 41 (FIG. 5), with a configurationknown to those skilled in the art. FIG. 5 again shows rolls with twodifferent diameters, which can be handled by the same device without theneed for specific adjustments. It must be understood that in actual factwhen the diameter of the roll changes, the side elements 41 with therelative mechanisms supported thereby will move upwards or downwards,while the chain 13 and the sliding channel 9 of the rolls remains at thesame height. This facilitates adjustment of the machine.

Also provided on the side elements 41 are fixed guides 43 and 45, whichcooperate with lateral grooves of the contact members 29, to prevent theflexible member 23 from jolting along the rectilinear branches.

It is understood from the description above that one of the importantaspects of the device consists in the fact that the trimmings areeliminated by being positioned at the level of an area of the flexiblemember 23 devoid of contact members 29. When the length of the series ofrolls R varies, due for example to variation in the width of the ply ofpaper with which the logs are produced, no adjustments or settings areneeded, nor do any components require to be replaced. In fact, only theadvance speed of the flexible member 23 must be adjusted. Moreover, thelength of the flexible member 23 can be substantially shorter than theseries of rolls to be handled, that is, of the logs L. In fact, asobserved above, the head and tail trimmings Rt and Rc are eliminatedthanks to the absence of contact members 29 in a portion of the flexiblemember 23. It has also been observed that these contact members have thefunction of drawing forward only the first roll R1, to accelerate andthen decelerate it in order to increase the reliability of eliminationof the head trimming Rt. They also have the function of pushing the lastrolls when the pusher 11 is no longer in contact therewith.

Advantageously, the member 23 and the contact members 29 can alsoaccelerate the last roll RN to increase reliability of unloading of thetail trimming Rc and to distance the rolls from the pusher 11 allowingit to invert its trajectory without having to decelerate and withoutinterfering with the final roll RN. In the interval between the phasesto draw the first and the last roll of each row the flexible member 23can remain at a standstill, for example in the position in FIG. 2, whilethe row of rolls R slides under the contact members 29 which in thisphase are only used for support. It is therefore possible to produce avery short flexible member 23, even much shorter than the one shown inthe accompanying drawing, reducing the section thereof devoid of contactmembers 29, that is, reducing the distance between the members 29A andthe members 29B. Variation in speed of the motor 28 allows the positionof the contact members 29A always to be returned in phase with the firstroll R1 and the contact members 29B with the last roll RN of each row,and hence the area of the flexible member 23 devoid of contact members29 to be returned in phase with the position of the tail trimmings Rc ofa series of rolls and the head trimmings Rt of the consecutive series.

FIGS. 8 to 12 show a further embodiment of the invention. Similar orcorresponding elements are designated with the same reference numbersused in FIGS. 1-7. The cutting machine placed upstream of the trimremoval device is not shown.

The rolls R produced by cutting each log L by means of the cuttingadvance under the push of a respective pusher 11 connected to a chain 13or other suitable flexible member. Several pushers are fixed to thechain 13 in suitable positions, according to a known layout. These arealso used to make the logs advance through the cutting machine. Thechain 13 is driven about return wheels 15. This wheel is motorized by amotor equivalent to motor 17, interfaced with a control unit equivalentto unit 19. Both the motor 17 and the control unit 19 are not shown inFIG. 8 for clearer and simpler representation.

Disposed between the chain 13 and the delivery conveyor 7 is a fixedlongitudinal supporting element 21, in the form of a bar having circularcross section (see in particular FIG. 9). The rolls R slide along thesupporting element 21 towards the conveyor 7.

Extending above the fixed longitudinal supporting element 21 is aflexible member 23, in the example shown formed of a pair of chainsdriven about a pair of toothed return wheels 25, 27. The toothed wheels27 are motorized by an electronically controlled, variable speed motor,not shown, similar to motor 28 in FIG. 1, interfaced with the centralunit 19, just as the motor 17.

In this embodiment the chains forming the flexible member 23 are notvertically aligned above the supporting element 21. Rather, as can beseen in FIGS. 9 and 11, the flexible member is laterally staggered withrespect to the supporting element 21 such that the latter is placed on aside of the vertical plane of symmetry of the flexible member 23, i.e.the geometrical plane with respect to which the chains 23 aresymmetrically arranged. The arrangement is such that the pusher 11 canpass on the side of the supporting element 21, the pusher beingsymmetrically disposed with respect to the two chains 23. In this waythe pusher 11 does not require to be slotted as shown in 11A in theprevious figures.

Disposed along a portion of the flexible member 23 are a series ofcontact members 29, adjacent to one another, providing a lateral supportfor the rolls R made to advance in the device 1. As can be seen inparticular in FIGS. 11 and 12, all the contact members, with theexception of the initial member 29A and the final member 29B arecomposed of simple flat bodies, having a substantially verticallyextending finger portion, indicated with 29F designed to come intocontact with the side surface of the rolls R. As can be seen in FIG. 11,each roll contacts the vertical finger 29F and the support element 21 intwo points arranged such that the roll does not fall down, but issupported by said two mechanical elements. Actually, each roll can besupported on one side by more than just one contact element 29, as canbe appreciated from FIG. 8.

Each contact member 29 is provided with two projections or appendages A1and A2 engaging into guiding channels 143 and 145 supported by a frame,not shown.

As can be seen in the cross-section of FIG. 11, the contact elements 2917. are provided only on one of the two chains 23, while the other chainis free of said contact elements 29. More specifically, the chain whichis provided with contact elements 29 is the one which is farther awayfrom the supporting element 21. This is due to the fact that each roll Rhas to lean on the contact elements 29 on the side opposite thesupporting element 21.

The members 29A and the members 29B, which constitute the end members ofthe series of contact members carried by the flexible member 23, delimita section or portion of the flexible member 23 which is devoid of saidcontact members. This section devoid of contact members 29, 29A, 29B isphased with respect to the position of a pusher 11 and of the tailtrimming and head trimming Rc and Rt of two subsequent series of rollsR, so that the trimmings of each series of rolls are always positionedat the level of the section devoid of contact members 29, 29A, 29B.

As best seen in FIGS. 9 and 10, each contact member 29A, 29B is shapedin the form of a gripper including a pair of jaws 29X. Each jaw 29Xincludes a slider 29Y and a shoe 29Z hinged at 32 to the respectiveslider. Helical springs C keep the shoes 29Z in an open position (seeupper pair of shoes in FIG. 9). Each shoe 29Z is further provided withprojections B, which are forced by the springs C in a position ofminimum distance (see again upper pair of shoes in FIG. 9).

Each slider is provided with two appendages, again designated A1, andA2, engaging in the sliding guides 143, 145 respectively and havingsubstantially the same shape as the appendages A1, A2 of the contactingmembers 29 (FIGS. 11 and 12) arranged between members 29A and 29B.

Disposed along at least a portion of the lower branch of the flexiblemember 23 is a fixed control profile 37, with respective inclined endportions, forming cam profiles. This control profile acts on theprotrusions B of each shoe 29X of the contact members 29A and 29B whenthey pass under and along said profile 37 and produce a thrust thereonwhich causes the respective shoes 29X to oscillate around pivot points32 against the action of springs C. This causes the roll R arrangedbetween the shoes 29X to be grasped by said shoes. Each of the twoterminal contact members 29A, 29B act, therefore, quite in the samemanner as forceps or pliers to grasp the roll R which is located betweenthe shoes.

The device shown in FIGS. 8 to 12 operate quite in the same way as thedevice of FIGS. 1-7. However, the first roll R1 and the last roll RN ofeach row or series of rolls is not grasped by way of a pushing forceexerted by the terminal contact members 29A, 29B. Rather they aregrasped laterally by the forceps formed by each pair of shoes 29X ofsaid terminal contact members 29A, 29B. The first and last roll of eachrow is thus firmly and safely grasped but is not damaged, since it isnot pushed against a fixed surface along which it is caused to slide.The force with which each roll R1, R, RN leans on the longitudinalsupporting element 21 is due only to the own weight of the roll.

Acceleration, deceleration, stopping and any speed variation andsynchronization of the upper flexible member 23 is essentially the sameand for the same purposes as described above with respect to FIGS. 1-7,such that a detailed description of the dynamic behavior of the devicecan be dispensed with.

It is understood that the drawing purely shows a possible embodiment ofthe invention, which may vary in forms and arrangements without howeverdeparting from the scope of the inventive concept. Any referencenumerals in the appended claims are provided for the sole purpose offacilitating reading in the light of the description hereinbefore andthe attached drawings and do not in any manner limit the scope ofprotection.

1. A device to eliminate trimmings or scraps from series of productscomprising: at least a continuous movable flexible member (23) carryinga series of contact members (29, 29A, 29B) for the products (R; R1; RN)aligned with one another, a section of said movable flexible memberbeing devoid of said contact members to allow trimmings (Rc, Rt) tofall; at least a longitudinal supporting element (21) of the products(R; R1, RN), parallel to said movable flexible member, the reciprocalposition of said flexible member and of said longitudinal element beingsuch that the products advance in contact with the contact members (29,29A, 29B) of the flexible member and with the longitudinal element; atleast a pusher (11) to insert the series of products with respectivetrimmings between said flexible member and said longitudinal supportingelement; characterized in that said flexible member (23) is controlledwith a variable speed to carry the section thereof devoid of contactmembers every time to the level of the tail and head trimmings (Rc; Rt)of two consecutive series of products.
 2. Device as claimed in claim 1,characterized in that said longitudinal supporting element (21) isfixed.
 3. Device as claimed in claim 1 or 2, characterized in that saidcontinuous flexible member (23) has at least a first contact member(29B) designed to grasp at least the last product (RN) of each seriesand make it advance.
 4. Device as claimed in claim 1, 2 or 3,characterized in that said continuous flexible member (23) has at leasta second contact member (29A) designed to grasp at least the firstproduct (R1 of each series and make it advance.
 5. Device as claimed inone or more of the previous claims, characterized in that at least someof the contact members (29) are provided with a contact surface for theproducts having a low friction coefficient, to allow said products toslide with respect to said supporting members.
 6. Device as claimed inone or more of the previous claims, characterized in that said flexiblemember (23) is controlled at a variable speed to accelerate at least thelast product (RN) of each series with respect to the pusher therebehind(11).
 7. Device as claimed in one or more of the previous claims,characterized in that said flexible member (23) is controlled at avariable speed to accelerate and, if necessary, subsequently decelerateat least the first product (R1) of each series with respect to thesubsequent product.
 8. Device as claimed in one or more of the previousclaims, characterized in that said flexible member (23) is controlled toadvance at a lower speed or to stop during an interval of time betweenarrival of the first product (R1) and arrival of the last product (RN)of each series, during said interval of time the products being pushedby said pusher (11) and sliding along the flexible member (23) restingon the contact members (29).
 9. Device as claimed in at least claims 3and 4, characterized in that one or more contact members (29A, 29B)disposed at each end of the series of contact members carried by saidflexible member (23), adjacent to said portion of the flexible memberdevoid of contact members, can be operated to have an grasping effect onthe products in contact therewith.
 10. Device as claimed in one or moreclaims 3, 4 or 8, characterized in that said contact member or membersdesigned to grasp said products are mounted movable, with respect to theflexible member (23) which carries them, at least in a directionessentially orthogonal to said flexible member.
 11. Device as claimed inone or more of claims 3, 4, 9 and 10, characterized in that the contactmembers (29A, 29B) designed to grasp the products have a movable portion(31, 33, 33T; 29X).
 12. Device as claimed in claim 11, characterized inthat a fixed control profile (37) acts on said movable portions, anelastic element (35) being provided to hold each said movable portion incontact with said fixed control profile.
 13. Device as claimed in one ormore of the previous claims, characterized in that said flexible member(23) and said longitudinal supporting element (21) are arranged oneabove the other.
 14. Device as claimed in claim 13, characterized inthat said flexible member (23) and said longitudinal supporting element(21) are approximately vertically overlapped with each other.
 15. Deviceas claimed in claim 13, characterized in that said flexible member (23)is laterally staggered with respect to said longitudinal supportingelement (21).
 16. Device as claimed in any one of claims 13 to 15,characterized in that said longitudinal supporting element is positionedunder said flexible member.
 17. Device as claimed in one or more of theprevious claims, characterized in that said flexible member (23) iscontrolled to be accelerated synchronously with the position of saidpusher, to distance the last product (RN) of each series from the pushertherebehind.
 18. Device as claimed in one or more of the previousclaims, characterized in that said flexible member (23) is controlled tobe accelerated synchronously with the position of said pusher, todistance the first product of each series at least temporarily from thesubsequent product.
 19. Device as claimed in one or more of the previousclaims, characterized in that said flexible member (23) includes a pairof parallel chains, one of said chains being provided with a pluralityof intermediate contact members (29), said intermediate contact membersbeing arranged in a laterally staggered position with respect to saidlongitudinal supporting element (21).
 20. Device as claimed in claims 3and 19, characterized in that said first contact member (29B) designedto grasp at least the last product (RN) of each series of productsincludes two shoes (29X) and that means are provided to control agrasping motion of said shoes.
 21. Device as claimed in claims 4 and 19or 4 and 20, characterized in that said second contact member (29A)designed to grasp at least the first product (R1) of each series ofproducts includes two shoes (29X) and that means are provided to controla grasping motion of said shoes.
 22. Device as claimed in claim 20 or21, characterized in that the two shoes (29X) of said first and secondcontact members (29A, 29B) are controlled by a fixed cam profile, whichcontrols a closing motion of said shoes.
 23. Device according to one ormore of claims 20, 21 or 22, characterized in that each shoe (29X) ofsaid first or second contact member (29B, 29A) is carried by arespective one of said chains.
 24. Device as claimed in claim 3 or 4,characterized in that at least one of said first and second contactmembers (29A, 29B) designed to grasp said products include jaws orpliers shaped grasping members.
 25. Device as claimed in one or more ofthe previous claims, characterized in that said at least one pusher hasa slot (11A) in which the longitudinal supporting element (21)penetrates when said pusher pushes the products between the longitudinalsupporting element and the flexible member.
 26. Device as claimed in oneor more of the previous claims, characterized in that said products arerolls obtained from cutting a log.
 27. Method to eliminate head and tailtrimmings (Rt, Rc) from a series of aligned products (R, R1, RN),wherein a series of products is pushed by a pusher (11) between alongitudinal supporting element (21) and a continuous movable flexiblemember (23) equipped with contact members (29, 29A, 29B), said contactmembers being in contact with the products which advance between saidflexible member and said longitudinal supporting element, said flexiblemember having a section devoid of contact members at the level of thehead and tail trimmings (Rt, Rc) of said series of products to causesaid trimmings to fall, characterized in that said flexible member (23)is controlled at a variable speed to carry the section thereof devoid ofcontact members every time to the level of the head and tail trimmings(Rc; Rt) of two consecutive series of products.
 28. Method as claimed inclaim 27, characterized in that said longitudinal supporting element isheld fixed.
 29. Method as claimed in claim 27 or 28, characterized inthat said products are made to advance parallel to said supportingelement and at least the last product of each series is grasped by meansof said contact members to make said product advance along saidsupporting element by means of said flexible member (23) when saidpusher (11) loses contact with the series of products.
 30. Method asclaimed in claim 29, characterized in that the speed of said flexiblemember is varied to accelerate at least the last product of each seriesto distance said product from said pusher.
 31. Method as claimed in oneor more of claims 28 to 30, characterized in that the speed of saidflexible member is varied to accelerate the first product (R1) of eachseries to distance said product from the subsequent product.
 32. Methodas claimed in claim 31, characterized in that the first product of eachseries is subsequently decelerated, said acceleration and subsequentdeceleration guaranteeing that the head trimming (Rt) of each series ofproducts falls.
 33. Method as claimed in one or more of claims 27 to 32,characterized in that said contact members are temporarily stopped ormade to advance at least temporarily at a lower speed to the advancespeed of the products determined by the speed with which they are pushedby the respective pusher, the products sliding with respect to saidcontact members while resting thereon.
 34. Method as claimed in one ormore of claims 27 to 33, characterized in that said longitudinalsupporting element is disposed under said flexible member.
 35. Method asclaimed in one or more of claims 27 to 34, characterized in that saidflexible member and said longitudinal supporting element are essentiallyvertically overlapped with each other.
 36. Method as claimed in one ormore of claims 27 to 35, characterized in that one or more of saidcontact members are pressed at least temporarily against the lastproduct of each series, to grasp said product.
 37. Method as claimed inone or more of claims 27 to 36, characterized in that one or more ofsaid contact members are pressed at least temporarily against the firstproduct of each series, to grasp said product.
 38. Method as claimed inone or more of claims 27 to 35, characterized in that at least one ofsaid contact members laterally grasp the first or the last product ofeach series of products.
 39. Method as claimed in one or more of claims27 to 38, characterized in that said pusher is made to advance betweensaid flexible member and said longitudinal supporting element. 40.Method as claimed in claim 39, characterized in that said longitudinalsupporting element is made to penetrate a slot produced in said pusherto allow advance of the pusher and inversion of the trajectory thereof.41. Method as claimed in one or more of claims 27 to 40, characterizedin that said products are rolls obtained by cutting a log.
 42. A cuttingmachine to cut logs of web material wound in rolls, characterized inthat it comprises a device to eliminate the trimmings as claimed in oneor more of claims 1 to 26.